package com.cjst.util;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.security.MessageDigest;

import org.apache.commons.codec.binary.Hex;
import org.apache.commons.codec.digest.DigestUtils;

public class Md5Util {
		 
		/**
		 * 获取一个文件的md5值(可处理大文件)
		 * @return md5 value
		 */
		public static String getMD5(File file) {
			FileInputStream fileInputStream = null;
			try {
				MessageDigest MD5 = MessageDigest.getInstance("MD5");
				fileInputStream = new FileInputStream(file);
				byte[] buffer = new byte[8192];
				int length;
				while ((length = fileInputStream.read(buffer)) != -1) {
					MD5.update(buffer, 0, length);
				}
				return new String(Hex.encodeHex(MD5.digest()));
			} catch (Exception e) {
				e.printStackTrace();
				return null;
			} finally {
				try {
					if (fileInputStream != null){
						fileInputStream.close();
						}
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
		}
	 
		/**
		 * 求一个字符串的md5值
		 * @param target 字符串
		 * @return md5 value
		 */
		public static String MD5(String target) {
			return DigestUtils.md5Hex(target);
		}
	 
//		public static void main(String[] args) {
//			long beginTime = System.currentTimeMillis();
//			File file = new File("E:\\imgWork\\apk\\ape.apk");
//			String md5 = getMD5(file);
//			long endTime = System.currentTimeMillis();
//			System.out.println("MD5:" + md5 + "\n 耗时:" + ((endTime - beginTime) / 1000) + "s");
//		}
}
